Esters of aromatic olefinic phosphinic acids



ESTERS on AROMATIC: OLEFINIC PHOSPI-HNIC' ACIDS- Alan R. Stiles, Berkeley, and Denlia'n'iflnrman, Orlnda,

Calif., assignorsto Shelli Development Company, Emeryville, Califi, a corporationof Delaware No Drawing. Application November-'24, 1952,

Se ial No.322,355

This application is a continuation-impart of our copending application Serial No. 122,152 filed October 18,

1949 now abandoned. v a t This invention relates to newesters of phosphinic acids, in which both an aromatic radical and an olefinic radical are attached to phosphorus. More particularlythe invem tion provides new polymerizable aromatic org'ano-phosphorus compounds containing the polymerizable reactive grouping in an open chain of carbon atomsfdirectly linked to phosphorus, and polymers of the new compounds;

It appears that the only-polymerizable aromatic organophosphorus compounds known prior to our invention more lower alkylfg'roups as the only'substituents, theglower were those in which polymerizable reactive groupings were contained in esterifying radicals; e; g., diallyl phenylphosphonate, and the like compounds. The compounds provided by our invention each'contain such grouping in an open chain of carbon atoms linked tophosphorus by a C-P bond, a type of'bond which has'proven to be vastly more stable than aC--OP bond T The novel esters of our invention are the esters of phosphinic acids, which'esters are represented bythe formula Y sax:

in which Ar represents a member of the class consisting of the phenyl group and the alkyl-substituted phenyl groups, R representsv at lower vZ-alkeuyl group,candl represents a lower-unsubstitutedaliphatic hydrocarbon group containing not more than one-unsaturated linkage. Examples of the compounds provided by the invention are methyl benzene(2 propene)phosphinate, methallyl benzene(2-propene)phosphinate, decyl benzene(2-methyl- 2-propene)phosphinate, isopropyl tertiary-butylbenz ene- (2-propene)phosphinate, 'pe'ntyl benzenet2-butene)phqs phinate, methyl p-toluenet2-ethy1-2-propene)phosphiriate, 2-ethylhex'yl 2,3,5-trimethylbenzene(2 butene)phosphinate, benzyl 3,5-di-t-butylbenzene(2-propene)phosphinate, 3,3,5 trimethylhexyl 3,5 diethylbenzene(2"- methyl 2- propene)phosphinate, isobutyl 3,5-diisopropylbenzene(2- ethyl 2 propene)phosphin'ate, allyl' 4-n-butylbenzene(2- methyl-Z-propenn)phosphinate, hexyl -2,3,Strimethylbenzene(2-propene)phospliinate, butyl 4-dodecylbenzene(2- propene)phosphinate, and allyl pen'tem'ethylbenzene (2- ethyl-4-methyl-2-heptene)phosphinate,

The group represented by Ar thus will be seen to be the phenyl group or aphenyl group having one or more of the hydrogen atoms replaoed lziy-alkyl substituents, each ance' with} equation stituentsselected from the methyl, ethyl, 'propyl, butyl, secondary but'yl, isobutyL and tertia'ry'bu't'yl groups.

jIhe lowerILalkenyl:group represented by R may be straight-chain or-branched-chain. By the term,lower- 2-alkenylfgt0up? reference is made tothe allyl group and, the allyl groups which are substituted byv one or Z -aIkenyl 'grOUP preferably containing from three'to ten carbon 'atomsflAlthough the inventionis' not ,-,limited thereto, the most-valuable novel monomeric compounds of the invention" arefthose inrwhich the 2-alknyl group v contains the unsubstituted ,methylidene group (CI-12 as in theallyl group, the rnethallyl group,- etc.

' The aliphatic'hydrocarbon grouprepresentedby R fmay. be saturated, as inthe preferred compounds of the invention, or it may contain one'unsaturated 'carbon-to-carbon linkage; Bythe term lower unsubstituted aliphatic hyel drocarbon group containing notmore, than'oneunsatu- I rated linltagef reference thus is made to the lower. alkyl groups and to the lower alkenyl groups, such as. allyl, me'thallyl, vinyl, isopropyl, decylpcrotyl, 3e-pentenyl, 2- mathyLS-butyh-Z -yl, 2-ethylhexyl, and amyle (The aliphatic hydrocarbon group represented by Rjbeinga-lowcr' about tencarbonatoms.

aliphatic hydrocarbon group, ,will containffron'rone to In addition to theirv utility as polymeriaable intermediates the esters of this invention are of interestfor use p i as additives to lubricants, of the naturally occur'ring or petroleumbased variety, aswell as ofthe synthetic type,

endV'rorLuS-e as flame retardantsandiasingredients in plastic or ,resinous compositions, e. g., as polymerizable V lllle'lsticizers.

- "It has been' indicatedthat organo-phosphorusl compounds containing a single polymerizable"C=C-group in an opentchainio f carbon atoms linked-to aphosphorus' :7

atonf are incapable of'homopolymerizingunder the usual 2,432,214). Surprisingly,'the esters provided by the presen "rivention readily undergohomopolymerization. ,f A' particularly ,eonvenientmethod of preparing the esters of our inventionconsistsof reacting an ester of an aromatic 1 phosphonous acid with an allyl-typehydro carbon halide, i'.;e.,"beta,gammaeolefinically unsaturated" hydrocarbonhalide, The reaction proceeds in accordand X is anatom of halogen, preferably chlorine or bromine; The reaction can be carried outin the manner and under the conditions corresponding to those that are suitable for carrying out the well-known Arbusov reaction. .In the Arbusov reaction alkyl halides react withl-t-rialkyl phosphitesto produce, presumablyqviaad-j ditiouand Qisomeriz ation, a dialkyl alkane phosphonate in which .the alliance residue directly, substituted on the phosphorus atom is derived from, the alkyl group of. the

: allfi-yl halide: j,Th e'Arbusov reaction conveniently may be of which substituents may contain from one to twelve or more carbon atoms. Although the invention 'is'riotfllimited as to number or 'length-oflalkyl 'groups'whichm'ay' substituted on'the" phenyl group" represented; by 'A'r, the most desirable compounds of theinvention those in whichthe phenyl group, representedby Ar,' 'coiitains'from none to three alkylsubstituents, each" containing'from one-t0 four carbon atoms, i. e., the'phenylgroupand.

the phenyl group having either one; two, or three *subcarbon atoms, The halogen preferably is bromine or 7 chlorine, although iodides can also'be used. By the Patented June 21,1955

Ar, .R,.andj R. are defined as hereinbefore,

carried iou'tlbyheating inea sealed tubeonunder reflux, a mixture of the trialkylphosphite and the alkyl halide at a suitable elevated temperature, e. g., from'about t C.

term beta,gamma-olefinically unsaturated hydrocarbon halide we mean that the hydrocarbon halide has one atom of halogen and that one in the allyl position relative to the olefinic bond, i. e., substituted on a saturated carbon atom which in turn is directly bonded to an olefinically unsaturated carbon atom. Esters of aromatic phosphonous acids which are useful for the preparation of the preferred compounds of the invention are those which contain from one to about ten carbon atoms in each alcohol residue. In other words, each OR in the preceding equation preferably will represent the residue OR of an alcohol ROH containing from one to about ten carbon atoms. The most readily prepared and hence preferred esters of our invention are those in which the group represented by Ar contains from six to about eighteen carbon atoms.

The polymeric compounds provided by our invention are prepared by polymerizing, i. e., by homopolymerizing or by copolymerizing with other polymerizable compounds, the monomeric compounds of our invention. The polymerization can be carried out by known procedures for the polymerization of polymerizable ethylenically unsaturated compounds. The polymerization usually will be carried out by heating the monomer or mixture of monomers which is to be polymerized in the presence of an added material which decomposes to yield free radicals, such as a peroxidic compound. The polymerization can be energized by heating at about the decomposition temperature of the added material, by exposure to actinic light or by equivalent means. The polymerization may be carried out in bulk, in solution, or in disperse phase. Examples of polymerization catalysts which may be used in or for the preparation of the novel polymers include, among others, di-tertiary-butyl peroxide, dibenzoyl peroxide, tertiary-butyl hydroperoxide, 2,2-bis(tertiary-butylperoxy)butane, tertiary-butyl perbenzoate, di-tertiary-butyl diperoxalate, hydrogen peroxide, ozone, diazomethane, and the like.

The esters provided by the present invention can be copolymerized with any compound capable of undergoing free radical-initiated copolymerization reactions. Such compound preferably will contain the vinylidene group (CH2=C and may be exemplified by the following: diallyl phthalate, vinyl acetate, diallyl ether, divinyl ether, allyl crotonate, methyl vinyl ketone, allyl ethers of glycerol, styrene, acrylonitrile, methyl methacrylate, vinyl chloride, vinylidene chloride and allyl acrylate. The copolymers may contain upwards from 5%, preferably from 50% to 95%, of the monomeric phospln'nic acid esters of our invention.

The following examples are presented for the purpose of illustrating the invention without the intent of limiting the same.

Example I CH2=GHCH2 O G/gOOHI The methyl benzene(2-propene)phosphinate was re covered as a colorless liquid boiling at 107-111 C. under 1-2 mm. mercury pressure. Analysis-Found, carbon 59.7%; hydrogen 6.7%; phosphorus 16.0%. Theory for CmHisOzP, carbon 61.2%; hydrogen 6.6%; phosphorus 15.8%.

Example 11 Methallyl benzene(2-propene)phosphinate is prepared by refluxing for 48 hours a solution consisting of 0.3 mole of dimethallyl benzenephosphinite and 0.6 mole of allyl bromide dissolved in cc. of benzene under conditions allowing the escape of methallyl bromide. The ester is isolated by fractionally distilling the reaction products. It has the formula CHr -CHOH: O

Analysis.Found, carbon 65.2%; hydrogen 7.5%; phosphorus 13.1%. Theory for CnHuOzP, carbon 66.0%; hydrogen 7.2%; phosphorous 13.2%.

Example III CHFC (CH1) CH: O

i OGHa Example IV Butyl benzene(2-propene)phosphinate is prepared by heating together about equimolar amounts of dibutyl benzenephosphinate and allyl bromide and when the reaction has gone to completion fractionally distilling the resulting mixture. Butyl benzene(2-propene)phosphinate has the structural formula 107 C. at 0.1 mm. mercury pressure. Refractive index (n 20/D) 1.5113. Analysis.Found, 12.8% phosphorus. Theory, 13.0% phosphorus.

Example V Decyl 2,3,5 trimethylbenzene(2-ethyl+2-propene)phosphinate is prepared by heating in a sealed tube a mixture of about 2 moles of 3-chloro-2-ethylpropene and about 1 mole of didecyl 2,3,S-trimethylbenzenephosphinate and fractionally distilling the resulting mixture. The product has the formula CH5=C (C1115) CH1 0 -OCmHn Example VI and withdrawn from the system as the reaction progresses. At the end of the reaction period the reaction mixture is fractionally distilled to recover the product.

The formula for butyl 3 ,S-dibutylbehzne(Z-butene)r phosphinate is as follows:

CHaCH=CHCH1 04B:

-o'-omomcmcm Example VII V I Poly[methyl benzene(2vpropene)phosphinate] is prepared by heating to a temperature of 115 C. for '24 hours 4 V a solution consisting of grams of methyl benzene- (2-propene)phosphinate and 1.0% by weight of; di-- tertiary-butyl peroxide. The viscous, liquid, thermo plastic polymer is isolated'by distillin g ofi the volatile components of the mixed reaction products. It predominates in reoccurringstructural units of'the Example VIII A copolymer of diallyl phthalate with methyl benzene (2-propene)phosphinate is prepared by heating to a temperature of 115 C. for 24 hours a solution' consisting of 8.0 grams of diallyl phthalate, 8.0 grams .of methyl benzene(2-propene)phosphinate and 3.5% by weight of di tertiary-butyl peroxide (basedupon the total weight, of esters). The polymer is obtained as a colorless solid. 1 V a While various modifications of the. present invention have been disclosed, it is to be understood that the in formula- 25 formula slightly plastic,

' 7. A c mp the formula".

vention is not limited thereto, but may be varied'within Y the letter and spirit of the followin We claim as our invention: 7 1. Methyl benzene(2-propene)ph0sphinate having the structural formula ll P-o on,

g claims.

I CHr=CH-C 2 g 2. A copolymer of diallyl phthalate with an about equal weight of methyl benzene(2-propene)phosphinate having the structural formula (Japan-c formula P 1 3. Methallyl benzene(2-propene)phosphinate having the structuralformula V J 7 v g vh-ocut rgom a a -c 3- I benzene(2 ethyl 2 propene)-. phosphinate having the formula 1 f-':. .=i =m v V t Butyl benzene(2 propehe)phosphinate having 7 the 6. .Allyl benz ene(2-propene)phosphinatel having theg 7 group containing not'more than .one unsaturated linkage; I

8. The polymer of a compound defined in claimj. a 9.- A polymer' of methyl ,benzene(2-propene) phos- V r l 4 phinate which pho'sphinate hasth'e structural formula 1 "GHFCVHQCHQ 7 p ReferencesCitedinthe-fileof thispatent "UNITEDVSTATES PATENTS 

7. A COMPOUND HAVING THE STRUCTURE REPRESENTED BY THE FORMULA 